Prey selection and capture strategies of the benthic hydroid Eudendrium racemosum

• Published in: Marine ecology. Progress series (Halstenbek) Vol. 47; no. 1; pp. 83 - 88
• Main Author: Barange, M
• Format: Journal Article
• Language: English
• Published: Inter-Research 01-01-1988
• Subjects: Chemical suspensions; Diet; Eudendrium racemosum; Filtration; Marine ecology; Nematode larvae; Plankton; Population parameters; Population size; Population structure; Zooplankton
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps047083

This paper examines prey capture strategies of a passive benthic suspension feeder, the hydroid Eudendrium racemosum (Cavolini, 1785), in relation to its biometry, size structure of particles captured, and size structure of potential prey. Results demonstrate: (1) polyp size is relatively fixed and constant for all zooids of the colony; (2) size structure of prey items is similar to that of the natural zooplankton population; (3) prey selection cannot be demonstrated for most prey groups. These points favor a model of capture strategy, here referred to as Multidirectional Feeding Strategy; it conceptualizes prey capture as the result of the interaction of direct interception, inertial impactation, and gravitational deposition. This model may be extrapolated to other colonial benthic suspension feeders, the relative importance of the different mechanisms depending upon organismic size and habitat conditions. Our results suggest that past models, proposed on the basis of laboratory experiments, oversimplify the process of prey capture because they fail to consider adequately all the mechanisms involved.